我怎样才能转换List成Optional<List>？
以下代码生成编译错误:
public Collection<Optional<UserMeal>> getAll() {
Comparator comparator = new SortedByDate();
List<UserMeal> mealList = new ArrayList<>(repository.values());
Collections.sort(mealList,comparator);
Collections.reverse(mealList);
**List<Optional<UserMeal>> resultList = Optional.of(mealList);**
return resultList;
}